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Location of γ Aquilae above center |
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| Observation data Epoch J2000 Equinox J2000 |
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|---|---|
| Constellation | Aquila |
| Right ascension | 19h 46m 15.5795s |
| Declination | +10° 36′ 47.74″ |
| Apparent magnitude (V) | 2.724 |
| Characteristics | |
| Spectral type | K3II |
| U−B color index | 1.68 |
| B−V color index | 1.52 |
| Astrometry | |
| Radial velocity (Rv) | -2.8 km/s |
| Proper motion (μ) | RA: 15.72 mas/yr Dec.: -3.08 mas/yr |
| Parallax (π) | 7.08 ± 0.75 mas |
| Distance | approx. 460 ly (approx. 140 pc) |
| Absolute magnitude (MV) | -3.03 |
| Details | |
| Mass | 5 M☉ |
| Radius | 110 R☉ |
| Luminosity | 3000 L☉ |
| Temperature | 4100 K |
| Rotation | <17 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
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Gamma Aquilae (γ Aql, γ Aquilae) is a star in the constellation Aquila. It has the traditional name Tarazed (occasionally Reda), which appears to derive from Persian شاهين ترازو šāhin tarāzu "the beam of the scale", referring to an asterism of the Scale, α, β and γ Aquillae. Persian šāhīn means "royal falcon", "beam", and "pointer", and gave its name (as "falcon") to Beta Aquilae.
In Chinese, 河鼓 (Hé Gŭ), meaning River Drum, refers to an asterism consisting of γ Aquilae, β Aquilae and Altair.[1] Consequently, γ Aquilae itself is known as 河鼓三 (Hé Gŭ sān, English: the Third Star of River Drum.)[2]
In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Menkib al Nesr (منكب ألنسر - mankib al-nasr), which was translated into Latin as Humerus Vulturis, meaning the eagle's shoulder.[3]
Tarazed has an apparent magnitude of 2.72 and is of spectral class K3, giving it a decidedly yellowish orange hue in appearance. It is a giant star with a diameter of approximately half an AU, and its angular diameter can be detected and measured to be 0.0075 arcseconds. It is approximately 461 light years from Earth. The age of Gamma Aquilae is "only" about 100 million years. Nevertheless the star is already burning helium into carbon in its core.
In Chinese mythology, The Princess and the Cowherd, this star and β Aql, are children of Niulang (牛郎, The Cowherd, Altair) and Zhinü (織女, The Princess, Vega).
The Koori people of Victoria knew β and γ Aquilae as the Black Swan wives of Bunjil (Altair), the Wedge-tailed Eagle.[4]
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